There have been known optical coupling devices including a plurality of optical coupling sets, the sets each having a light-emitting element and a light-receiving element paired with each other within one package.
Such an optical coupling device has a tendency to cause so-called crosstalk in which light from one optical coupling set is received by the light-receiving element of another optical coupling set. In such instances, a signal is erroneously transmitted. The crosstalk can be prevented by separating the light-receiving elements of different sets from each other or providing a light shielding member between the light-receiving elements of different sets; however, an increase the overall size of the device package will tend to be required to accommodate such additional spacing between elements and/or shielding members.
In addition, when distance between the light-receiving elements is increased, a bonding wire used within the optical coupling device may become longer depending on the arrangement of the light-emitting elements and the light-receiving elements, which may result in a greater tendency for the bonding wire to become detached and/or a short circuit.